Your comments

I click on the big X of the last group of open tabs (on the Crome browser, not in TO)

-"Do you have "Continue where I left off"  enabled (well it is actually recommended to disable it if yes)?" Yes i have it enabled

-" is this happens every time on close?" Yes, unless i manually close all tabs from TabOutliner and then close TO

-"How long do you use Tabs Outliner (how many nodes you have? this can be seen if you collapse the root node)" I just formatted this pc a week ago and installed TO right away. I have the following nodes open:

Thanks for the fast answer!

Sorry but this is not fixed :(
I'm under Windows 7, Chrome v26.0.1410.64, the latest extension version and I still get this behavior.

Can I do something to help in locating this bug?